Floor covering and method



Patented Nov. 17, 1942 1 UNITED STATES PATENT OFFICE FLOOR COVERING AND METHOD John J. Bradley, Jr., Dedham, Mass, assignor to Bird & Son, inc.-, East Walpole, Mass., a corporation of Massachusetts No Drawing. Application February 27, 1939, Serial No. 258,725

Claims.

' as linoleum, rubber, or any of the compositions suitable to form a relatively thick wearing surface have been made by mixing together a mass of cork, wood powder and/or mineral matter and color, together with a binder. The binder in the case of linoleum is linoxyn and resins, or a binder of nitro-cellulose or resins may be used with such filling materials. These materials, after mixing, are formed initially into a dense sheet with or without a backing and, when cured, form a hard, dense, tread-resisting surface, through-andthrough decoration of which depends upon a pre-mixing of the color with the plastic mixture .at or before the time of application thereof to the colored plastic materials or depositing granulated material through stencils, thus limiting the designs which commercially can be made from the linoleum or like materials. Also, heretofore,

Graham and Lines, in their U. S. Patent No.

1,971,036, have described and claimed a floor covering not limited in design as is linoleum, rubber, or like materials, but which is made by first mixing a light colored mixture of wood powder and mineral matter with a small amount of primary binder (preferably nitrocellulose) with a very considerable amount of solvent to make a mass which can be formed into a layer on a base, and yet, because of the character and small amount of binder used, becomes sufiiciently open and absorptive in texture as to be printed with a liquid coloring material on the usual floor covering printing machines, and absorbs such an amount of the coloring material that the design of one or more colors and shades penetrates substantially the entire thickness of the tread-surface, after which the coloring material is dried durable tread-surface for floor covering in which the decoration retains its integrity throughout the useful life of said tread-surface. Such floor covering as just described has gone into considerable commercial use.

.The present invention provides an improved floor covering product and method of the general type of said Graham andLines patent, but presents many advantages-inboth method and product over said patent, as will hereinafter appear. In the commercial and preferred practice of the invention of said patent a plasticizer and relativelylarge proportion of solvent for the binder are required in order to form a plastic mixture that may be readily and smoothly sheeted on a exposed surface of the plastic mixture are adversely affected. Aside from their relatively high cost, there are also other disadvantages in the use of any considerable quantity of high-boiling plasticizers, for example, tr'i-cresyl phosphate, in that they remain in a liquid state and/or tend to interfere with the hardening of drying oil and, to whatever extent that they do either, tend to diminish the firmness and strength of the wearing layer. The product and method of the present invention avoid all of the difficulties just referred to and have, in addition,'various other advantages in product and method as will hereinafter appear.

The present invention contemplates the manufacture of floor covering involving a plastic mixture which, as applied to the base, may be, and desirably and preferably is, substantially in accordance with the following example (all parts being by weight):

200-300 parts wood powder ,substantially all passing a mesh screen, at least /2 passing a mesh screen, and a substantial portion passing a 200 mesh screen) 12 parts of aluminum stearate, zinc stearate, or other higher fatty acid zinc or aluminum water-insoluble salt, or a mixture thereof;

60 parts ofv Varnolene (mineral spirits), xylol, carbon tetrachloride, or other organic solvent, providing with the aluminum stearate a non-aqueous, relatively stiff and viscous gel which for convenience is herein termed a solvent-gel meaning the combination .of a non-aqueous solvent with a metallic salt of aluminum or zinc and stearic or equivalent higherv fatty acid;

0.01 part of cobalt, manganese, or lead metal as soluble drier added to Varnolene (mineral spirits);

-100 parts finely divided mineral pigment (usually white or neutral in color) to which, if desired, may be added parts of Lithopone, though, if desired, the plastic composition may be colored as required by colored mineral pigment;

50-225 parts of resins or equivalent hardenable material--a mixture of resin and drying oil which hardens is preferred, though various natural or artificial resins (somewhat plasticized or ,not), for example, phenol-formaldehyde resin, gums, rubberbodied linseed or other drying oils, will answer, any of said materials or combinations of the same being herein termed resinous material;

20-100 parts of Varnolene (mineral spirits) may be added to provide a wetter mix and thus facilitate sheeting.

In the preferred practice, after forming the aluminum stearate solvent-gel, the other plastic mixture constituents above set forth are added thereto and thoroughly mixed, preferably in a bladed mixer followed by a germans mixer so as to form a relatively stiff, nonfiowable gelled mixture, with or without theresinous material being present.

After having been thoroughly mixed, the plastic gelled mixture is, in commercial practice, by suitably driven rolls, frictioned in situ in layer form to the base to the thickness desired (say, .010" to .040") Because it is so well lubricated by means of the non-aqueous gel, the complete mixture under pressure is very easily workable and applied to a flexible base by means of the pair of calender rolls. Despite the fact that the mixture is non-fiowable, viscous, and stiff, the

non-aqueous gel permits it to be sheeted-readily with suificient adherence to the base but without adherence to the exposed roll, for the gell practically eliminates any adhesion to said roll by the resinous material or other constituents of the mixture.

The intermediate laminated product thus formed is then dried from two to' six hours at 150 F. and, as a result of this drying, the solvent passes off leaving the wood powder held together and to the base by the aluminum stearate, together with the resinous material, if it beemployed, thus providing a porous and uniformly open though still relatively strong and firm structure-the strength and firmness or hardness of the intermediate dried product of the above preferred proportions being materially greater than that-of said patent. A relatively large amount of resinous material may be employed, if desired, and still not appreciably affect the application of the plastic to the base or the color absorption of the dried sheet. The particles of wood powder are adhesively attached together by the resinous material and the solvent is carried between such coated particles, and, upon drying, gives the required porosity for printing. Moreover, the surface of the sheet is very smooth, due to the lubricating characteristics of the nonaqueous gel.

Following the drying off of the solvent and the hardening of the intermediate product due to such drying and the partial or complete hardening of the'hardenable resinous material, it is ready for the coloring or decorating step which may be done on a flat bed print machine or otherwise as desired so as to print on the intermediate product the desired design, though any method of applying color, rotary or flat bed, may be used. The coloring material may be a watersoluble dye or pigmented oil, through the latter is ordinarily employed in commercial practice, the pigments in such'case preferably being of extremely finely ground or colloidal type in drying oil so as to readily permeate into the intermediate product. The liquid color is ordinarily applied in the amount of approximately 35-45 lbs. per 100 sq. yds. of the material and the colored product, thus printed with the design, is dried for a period of several hours in a moderately heated oven, as a result of which, substantially all of the liquid carrier of the coloring material is evaporated ,and/or hardened. This step of drying or hardening the liquid carrier of the coloring material may serve to harden or further harden the resinous material, though, as a practical matter, the hardening thereof (whether by heat, oxidation, polymerization, etc.) may take place at any time during or after the drying off of the solvent from the gel.

The next operation is that of filling up the remaining voids or pores of the colored plastic mixture by adding thereto a suitable hardenable material, for example, drying oil, wax, or waxlike material, resin, lacquer,'or a mixture of two or more of them. The amount required for this purpose, because of the great strength of the intermediate printed product, is ordinarily of the order of 20 lbs. per 100 sq. yds. of the material, and this final filling operation may be done in either one or two coats, the result in either case being a marked increase in durability and strength as well as greatly improved appearance. In practice, drying oils such as linseed and Chinawood or their substitutes, have been found satisfactory, and there is ordinarily incorporated therewith a small amount of resin in order that the finished product may provide a firmer and harder surface and greater wear-resistance.

The hardening of these drying oils or other hardenable material may conveniently be accomplished by .a drying step such as that employed for drying the liquid carrier of the coloring material, or, the drying or hardening of the latter,

if a hardenable carrier is employed, may be accomplished at the same time as the hardening of thefilling material. It is also contemplated that the colors may be mixed with an additional binder and applied to the partially completed wearing layer. In the typical preferred product the completed wearing layer includes (by weight) 42% wood powder; 1.67% aluminum stearate; 21% resinous materials; 4.2% mineral pigment; with the balance made up of coloring material (dry) plus the after-applied or supplementaryfiller binder with a trace of the cobalt drier as metallic drier. Though the trace of cobalt or other drier performs no function in the finished product, it has a pronounced eflfect in enhancing the penetrating qualities of the dried sheet, though the reasons therefor are not fully understood. It appears to be important however that only very small amounts of the drier be used.

The product of this invention is found in practice to be denser and harder and more rigid than any heretofore made under said patent, and proface condition. It is also less susceptible to temperature changes and to water-primaril because it includes little or no liquid phase since the resinous material is hardenable to substantially solid form.

Having described my invention, what I- Wish to claim and secure by Letters Patent is:

1. The method of making a hard-surfaced floor ing 'off the solvent therefrom to provide a hardened smooth-surfacedthough porous, firm and adherent layer containing mainly said powdered wood, pigment, and hardened gel, and then applying thereto coloring and binding material to fill the pores thereof with said binding and coloring material extending through at least a major portion of the vertical depth of said wearing layer.

2. The method of making a hard-surfaced fioor covering comprising forming a non-aqueous relatively still and viscous'solvent-gel, said solventgel embodying a water-insoluble metallic salt of a higher fatty acid, the metal in said metallic salt being selected from the group consisting of aluminum and zinc, mixing therewith to form a relatively stifi non-flowable gelled mixture, finely powdered wood, coloring pigment, and resinous material, said mixture having lubricating characteristics, then applying to a flexible base a layer of substantial thickness of said nonaqueous mixture, then drying off the solvent therefrom to provide a hardened smooth-surfaced though porous, firm and adherent layer consisting mainly of said powdered wood, pigment, hardened gel, and resinous material, and then applying thereto coloring and binding material to fill the pores thereof with said binding and coloring material extending through at least a major portion of the vertical depth of said wearing layer.

3. The method of making a hard-surfaced floor covering comprising forming a non-aqueous relatively stiff and viscous aluminum stearate solventgel, mixing therewith to form a relatively still! non-flowable gelled mixture, finely powdered wood and coloring-pigment, said mixture having lubricating characteristics, then applying to a flexible base a layer of substantial thickness of said non-aqueous mixture, then drying oil the solvent therefrom to provide a hardened smoothand hardened gel, and then applying thereto coloringand binding material to fill the pores thereof with said binding and coloring material extending through at least a major portionof the vertical depth of said wearing layer.

4. The method of making a hard-surfaced floor covering comprising forming a non-aqueous relatively stiff and viscous aluminum stearate solventgel, mixing therewith to form a relatively stifl non-flowable gelled mixture, finely powdered wood, coloring pigment, and resinous material, said mixture having lubricating characteristics, then applying to a flexible base a layerof substantial thickness of said non-aqueous mixture, then drying off the solvent therefrom to provide a hardened smooth-surfaced though porous, firm and adherent layer consisting mainly of said powdered wood, pigment, hardened gel, and resinous material, and then applying thereto coloring and binding materialto fill the pores thereof with' said binding and coloring material extending through at least a major portion of the vertical depth of said wearing layer.

5. The method of making a hard-surfaced floor covering comprising forming a non-aqueous relatively stiff and viscous zinc stearate solvent-gel,

mixing therewith to form a relatively stiff nonflowable gelled mixture, finely powdered wood, metallic drier, and resinous material, said mixture having lubricating characteristics, then applying to a flexible base a layer of substantial thickness of said non-aqueous mixture, then drysurfaced though porous, firm and adherent layer a containing mainly said powdered wood. pigment,

ering produced in accordance with the method defined in claim 2.

8. A smooth hard-surfaced flexible floor covering produced in accordance with the method defined in claim 3. V

9. A smooth hard-surfaced flexible floor covering produced in accordance with the method defined in claim 4.

10.- A smooth hard-surfaced flexible floor covering produced in accordance with the method defined in claim 5.

' JOHN J. BRADLEY, Ja. 

